As is known in the art, RF power amplifiers having depletion mode, common source FET output transistors often use a separate transistor as a “drain switch” to turn on and off a DC drain supply power. An alternative to the use of a separate transistor as a “drain switch” is to use gate switching of the output transistor itself where a sufficiently negative voltage is supplied to the power amplifier's transistor gate to reduce the DC drain current to zero, shutting off the amplifier. A shortcoming of the gate switch is that during “amplifier bias up”, proper gate control of the amplifier might not be readily established and the drain current of RF amplifier might go unchecked causing system damage.